The invention relates to an electronic control for a glass forming machine.
In the case of a known control of this type (EP 0 603 011 B1) all controllers of the glass forming machine are connected to a common synchronization signal line and are also connected to each other by a stop line which is directed to one side, by a LAN (Local Area Network), by a bi-directional maintenance stop line and by a parallel-distribution transition signal line. One of the controllers has the additional task of controlling all other controllers. The cost is high and effectiveness is limited.
From U.S. Pat. No. 4,685,947 A it is known per se to control the controllers of the mechanisms of each section of the glass forming machine by means of a section controller. All section controllers are monitored by a common monitoring controller. An additional machine controller is connected to all controllers and to the monitoring controller. The constructional and wiring expense is also considerable in this case.
According to the earlier application publication no. EP 1 184 754 A2, a complete I.S. glass forming machine and peripheral devices, such as the gob feeder which is connected upstream and devices connected downstream at the so-called “hot end”, are controlled by a common control system. Two exemplified embodiments are disclosed in relation to this. In FIG. 2 the control system has a single central control unit which is connected via a serial CANbus (field bus) to a plurality of intelligent peripheral units. Each peripheral unit is also connected to a pneumatic or electric drive or to a sensor, and controls these drives or receives information from the electric drives or the sensors for local processing. This control system architecture is expensive. Faults in, or the failure of the central control unit lead to the whole production installation being disrupted or shut down.
In the other exemplified embodiment in accordance with FIG. 3 of the earlier EP 1 184 754 A2 the control system has three central units which are connected in a mutually parallel manner and are each connected to a common main CANbus. Each central unit is also connected by its own subordinate CANbus to a group of intelligent peripheral units. The first group controls all electric motors of the whole I.S. glass forming machine, the second group controls pneumatic molding movements of the whole I.S. glass forming machine and the third group serves to monitor the production installation equipment. This architecture is even more expensive. Faults in, or failure of a central unit lead to the whole I.S. glass forming machine being disrupted. The peripheral units cannot communicate with each other directly (for example for the purpose of mutual synchronisation).
From EP 1 122 218 A2 it is known per se to connect checking devices at the hot end behind an I.S. glass forming machine to the hub of a star network via a respective bi-directional line. The hardware ensures that the CAN elements connected to the hub have a serial structure in electrical terms.
It is the object of the invention of the invention to simplify the control of the glass forming machine and to make it more flexible.